Coil arrangement and model car having such coil arrangement

ABSTRACT

A model car with a coil arrangement having at least one substrate and at least one first coil portion and a second coil portion, wherein the substrate, which is manufactured from an electrical insulating material, has a basic shape extending in a planar manner and having an upper side and an underside opposite the upper side, wherein at least the first coil portion and the second coil portion form a coil winding, wherein the first coil portion is arranged on the upper side of the substrate and the second coil portion is arranged on the underside of the substrate.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a coil arrangement and a model car having such a coil arrangement.

2. Description of Related Art

A model car racing track, also known as a slot-car track or slot track, is a technical apparatus with which electrically-driven model cars can be driven in a guided manner along lanes.

The model car racing track comprises a track which can for example be assembled from a plurality of track sections which can be plugged together. The track can have two lanes which in each case possess a slot for guiding a model car and two bus bars for the current supply of the electrical drive of the model vehicles which can be moved along the respective lane. Current collectors on the respective model cars are thereby in contact with the respective bus bar in order to guarantee a transmission of electrical energy. The speed and braking behavior of the respective model car can in each case be controlled using a hand-held controller. However, when driving around a curve for example, due to centrifugal forces acting on the model cars it can happen that the contact between the bus bar and the current collector of the model car is interrupted, with the consequence that the energy supply to the electrical drive of the model car is interrupted and the model car loses speed.

SUMMARY OF THE INVENTION

The invention is therefore based on the object of providing a coil arrangement which is simple to manufacture and which takes up little construction space.

According to the invention, this object is achieved through a coil arrangement of the aforementioned type with the characterizing features of the independent claims. Advantageous embodiments of the invention are described in the further dependent claims.

The above and other objects, which will be apparent to those skilled in the art, are achieved in the present invention which is directed to a model car including a coil arrangement, the coil arrangement having at least one substrate and at least one first coil portion and a second coil portion, wherein the substrate, which is manufactured from an electrically insulating material, has a basic shape extending in a planar manner with an upper side and an underside opposite the upper side, wherein at least the first coil portion and the second coil portion form a coil winding, wherein the first coil portion is arranged on the upper side and the second coil portion is arranged on the underside of the substrate.

The substrate may have a ferrite core. The substrate may also have a first circuit board portion and a second circuit board portion, wherein an upper side of the first circuit board portion forms the upper side of the substrate and an underside of the second circuit board portion forms the underside of the substrate.

The model car may include connecting lines extending through the first circuit board portion and the second circuit board portion in order to connect the first coil portion with the second coil portion electrically. An underside of the first circuit board portion is arranged on an upper side of the ferrite core and an upper side of the second circuit board portion is arranged on an underside of the ferrite core.

The coil portions form at least three to eight, in particular five coil windings.

A screw vector (S) of the coil arrangement lies substantially within the plane of the substrate.

The substrate has a first direction of extension (I) which extends between the two coil portions, a second direction of extension (II) which extends at right angles to the first direction of extension (I) and a third direction of extension (III) which extends at right angles to the first direction of extension (I) and to the second direction of extension (II), wherein a screw vector (S) of the coil arrangement extends substantially in the direction of the second direction of extension (II) and/or the third direction of extension (III).

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a schematic sectional representation of an exemplary embodiment of a model car racing track according to the invention;

FIG. 2 shows a schematic representation of a transformer arrangement which is used in the model car racing track shown in FIG. 1;

FIG. 3 shows a view from above of the first substrate element shown in FIG. 2;

FIG. 4 shows a view from below of the second substrate element shown in FIG. 2;

FIG. 5 shows an operating scenario of the model car racing track shown in FIG. 1;

FIG. 6 shows a first wiring variant of bus bars of a track with two lanes;

FIG. 7 shows a second wiring variant of bus bars of a track with two lanes; and

FIG. 8 shows a further exemplary embodiment of a model car racing track according to the invention, with a track provided with a bus bar for each lane of the track, which has several lanes.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In describing the preferred embodiment of the present invention, reference will be made herein to FIGS. 1-8 of the drawings in which like numerals refer to like features of the invention.

An interruption-free energy supply can be achieved through a contact-free energy transmission. However, this requires a coil arrangement which is simple to manufacture and which takes up little construction space and which, arranged in a model car, forms a secondary element or coil of a transformer arrangement for supplying the model car with electrical energy, wherein the primary element of the transformer arrangement is assigned to the track.

For this purpose, in a coil arrangement of the aforementioned type, according to the invention the coil arrangement has at least one substrate and at least one first coil portion and a second coil portion, wherein the substrate, which is manufactured from an electrically insulating material, has a basic shape extending in a planar manner with an upper side and an underside opposite the upper side, wherein at least the first coil portion and the second coil portion form a coil winding, and wherein the first coil portion is arranged on the upper side and the second coil portion is arranged on the underside.

This has the advantage that in this way a coil arrangement is provided which is particularly compact and takes up little construction space. Furthermore, the manufacture of the coil arrangement is simplified in each case through the planar formation of the first and second coil portions on the upper or underside of the substrate, since planar or thick film technology can be used for this purpose.

According to a preferred embodiment, the substrate element has a ferrite core. As a result, the magnetic field is bundled and concentrated, so that the efficiency of the contact-free energy transmission is increased.

According to a further preferred embodiment, the substrate element has a first circuit board portion and a second circuit board portion, wherein an upper side of the first circuit board portion forms the upper side of the substrate element and an underside of the second circuit board portion forms the underside of the substrate element. Thus, the two circuit board portions can be formed from economical and easily workable circuit board material, wherein the first and second coil portions can be manufactured through etching of an electrically conductive coating, for example a copper coating.

According to a further preferred embodiment, connecting lines extend through the first circuit board portion and the second circuit board portion in order to connect the first coil portion with the second coil portion electrically.

According to a further preferred embodiment, an underside of the first circuit board portion is arranged on an upper side of the ferrite core and an upper side of the second circuit board portion is arranged on an underside of the ferrite core. In this way, a coil arrangement with a particularly compact construction form can be provided.

According to a further preferred embodiment, further coil portions form at least three to eight, in particular five, coil windings. In this way, a particularly efficient coil arrangement can be provided in order to guarantee a particularly efficient energy transmission.

According to a further preferred embodiment of the invention, a screw vector of the coil arrangement lies substantially within the plane of the substrate. In this way, a particularly effective and thus efficient coupling of the coil arrangement, as a secondary element of a transformer arrangement, with a secondary element can be achieved if the primary element is or comprises a bus bar extending longitudinally in the direction of travel of the model vehicle.

According to a further preferred embodiment of the invention, the substrate element has a first direction of extension which extends between the two coil portions, a second direction of extension which extends at right angles to the first direction of extension, and a third direction of extension which extends at right angles to the first direction of extension and to the second direction of extension, wherein a screw vector of the coil arrangement extends substantially in the direction of the second direction of extension and/or the third direction of extension. In this way, such a coil arrangement can be arranged so as to take up little construction space in a model vehicle.

The invention further relates to a model car having such a coil arrangement.

The invention is described in more detail in the following with reference to the drawings.

A model car racing track 2, also known as a slot-car track or slot track, is represented in FIG. 1.

The model car racing track 2 has a track 4 made up of a plurality of track sections which can be plugged together with, in the present exemplary embodiment, two lanes 6 a, 6 b, each for a model car 10. Only one model car 10 is illustrated in FIG. 1.

In the present exemplary embodiment, the track 4 has a recess (groove) 8 a, 8 b assigned to each lane 6 a, 6 b which is arranged centrally relative to the respective lane 6 a, 6 b and in which a guide element 30, for example a guide pin, of the model car 10, engages and so effects a guidance of the model car 10 along the respective lane, in this case the lane 6 a.

Furthermore, in the present exemplary embodiment the track 4 has in each case two bus bars 14 a, 14 b, 14 c, 14 d arranged on each side of the respective recess 8 a, 8 b which are assigned to the first lane 6 a or the second lane 6 b. The first and second bus bars 14 a, 14 b, 14 c, 14 d have a u-formed profile in cross section and are pressed into further recesses in the track 4.

The bus bars 14 a, 14 b, 14 c, 14 d are in each case formed in a single piece and of the same material. Furthermore, the bus bars 14 a, 14 b, 14 c, 14 d are manufactured of a magnetic material. In this way, the model car 10 can be held in the lane 6 a through magnetic force by means of a permanent magnet (not shown) which interacts with the bus bars 14 a, 14 b.

As will be explained later, the two bus bar pairs 14 a, 14 b or 14 c, 14 d form a primary element 18 of a transformer arrangement 16 for contact-free energy transmission to the model car 10.

The transformer arrangement 16 for contact-free energy transmission to the model car 10 also includes a secondary element 20 assigned to the model car 10 for coupling-in the electromagnetic field generated by the primary element 18.

In the present exemplary embodiment, the secondary element 20 is a coil arrangement 22.

In addition to the transmission of operating energy, control signals can also be transmitted with the transformer arrangement 16, for example in order to accelerate or brake the model car 10, for example in that these control signals are modulated with a higher frequency and filtered out again on the model car side.

Reference is now made, in addition, to FIG. 2, which for reasons of simplicity only shows the first lane 6 a of the two lanes 6 a, 6 b. However, the following explanations also apply analogously to the second lane 6 b with the recess 8 b and the bus bars 14 c and 14 d.

FIG. 2 shows that both the recess 8 a and also the two bus bars 14 a, 14 b each have a main direction of extension H pointing along the lane 6 a in the direction of travel, in which direction its dimensions are significantly greater than in the direction of the other directions of extension.

Furthermore, FIG. 2 shows that the coil arrangement 22 has a substrate 12. In the present exemplary embodiment, the substrate 12 has a first substrate element 24 a and a second substrate element 24 b as well as a ferrite core 26 arranged between the first substrate element 24 a and the second substrate element 24 b.

In the present exemplary embodiment, the first substrate element 24 a and the second substrate element 24 b are in each case circuit boards. The circuit boards have a basic shape extending in a planar manner, in the present exemplary embodiment a rectangular basic shape, with in each case an upper side and an underside opposite the upper side. They consist in each case of an electrically insulating material and conductor paths arranged thereon. Fiber-reinforced plastic is for example commonly used as insulating material. The conductor paths are for example etched from a thin coating of copper applied previously to the insulating material.

In the present exemplary embodiment, conductor paths on the upper side of the first substrate element 24 a form a plurality of first coil portions 28 a, while in the present exemplary embodiment further conductor paths on the underside of the second substrate element 24 b form a plurality of second coil portions 28 b. In each case one of the first coil portions 28 a and one of the second coil portions 28 b together form a coil winding of the coil arrangement 20.

For this purpose, connecting lines (not shown) are provided which extend through the first substrate element 24 a and the second substrate element 24 b and connect the respective first coil portions 28 a with the respective second coil portion 28 b in an electrically conductive manner. Thus, in the present exemplary embodiment the coil portions 28 a, 28 b form three coil windings. However, five to eight coil windings could also be provided.

Furthermore, FIG. 2 shows that the ferrite core 26 is arranged with its upper side on an underside of the first substrate element 24 a and the underside of the ferrite core 26 is arranged on an upper side of the second substrate element 24 b.

The ferrite core 26 is a component made of ferrite which, as core of the coil arrangement 22, increases its inductance or guides the magnetic field. Ferrites are understood to be materials comprising poorly electrically conductive or non-conductive ferrimagnetic ceramic materials made from the iron oxide haematite (Fe₂O₃), magnetite (Fe₃O₄), and/or from further metal oxides. Depending on the composition, ferrites are hard magnetic or soft magnetic.

The coil windings formed by the respective first coil portions 28 a and second coil portions 28 b have a screw vector S which, as illustrated in FIG. 2, lies substantially within the plane of the substrate 12 and describes the helical configuration of the coil windings of the coil arrangement 22.

It can also be seen that the screw vector S is arranged substantially at right angles to the main direction of extension H of the bus bars 14 a, 14 b.

Furthermore, FIG. 2 shows that the substrate 12 has a first direction of extension I, a second direction of extension II and a third direction of extension III.

In the present exemplary embodiment, the first direction of extension I extends in a height direction Z between the first substrate element 24 a and the second substrate element 24 b. The second direction of extension II extends at right angles to the first direction of extension I in the direction of the screw vector S or in a width direction Y. Furthermore, the third direction of extension III extends at right angles to the first direction of extension I and to the second direction of extension II in the direction of the main direction of extension H or in a depth direction X.

In the present exemplary embodiment, the substrate 12, the first substrate element 24 a, the second substrate element 24 b and the ferrite core 26 in each case have significantly greater dimensions in the direction of the second direction of extension II and the third direction of extension III than in the direction of the first direction of extension I. In other words, they in each case have a rectangular, in particular plate-formed basic shape.

Reference is now made, in addition, to FIGS. 3 and 4.

FIGS. 3 and 4 show that the first coil portions 28 a and the second coil portions 28 b have an elongated form, i.e., their respective dimensions in the direction of the third direction of extension III are greater than in the direction of the second direction of extension II. Furthermore, the first coil portions 28 a and the second coil portions 28 b extend at an angle to the second direction of extension II which is unequal to a right angle. In the present exemplary embodiment, the first coil portions 28 a and the second coil portions 28 b extend at an angle of 75° to 85° or 95° to 110° to the second direction of extension II.

In this way, a coil arrangement 22 is provided which is particularly compact and takes up little construction space. Furthermore, the manufacture of the coil arrangement 22 is simplified in each case through the planar formation of the first coil portions 28 a and the second coil portions 28 b on the upper or underside of the substrate 12, since planar or thick film technology can be used for this purpose.

The operation of the model car racing track 2 will be explained with additional reference to FIG. 5, wherein, for reasons of simplicity, of the primary element 18, only the first bus bar 14 a of the two bus bars 14 a, 14 b of the first lane 6 a is illustrated.

In operation, an alternating current with a frequency of 400 kHz flows through the bus bar 14 a. A magnetic field M is formed around the bus bars 14 a with concentric field lines extending around the bus bar 14 a. The course of the field lines can be described by a rotation vector R standing perpendicular to the plane which is described by the field lines.

The field lines pass through the secondary element 20 or the coil arrangement 22 and generate, through induction, an electrical voltage in the secondary element 20. The electrical voltage induced in the secondary element 20 can then be used to supply an electrical drive of the model car 10, so that the model car 10 can move in the direction of travel F predetermined by the main direction of extension H of the recess 8 or the bus bar 14 a. Thus, the direction of travel F and the rotation vector R are oriented substantially at right angles to one another. Substantially is thereby understood to mean within usual manufacturing tolerances.

A regulation of the speed of the model car 10 can thereby be achieved through a change in the current strength of the electrical current which flows through the bus bars 14 a, 14 b.

Due to the contact-free transmission of electrical energy, contact interruptions, such as occur in the prior art, can no longer lead to an interruption of the supply with electrical energy.

In addition to the first lane 6 a shown in FIG. 1, in the present exemplary embodiment the second lane 6 b for a second model car (not shown) is provided which has the same structure as the first lane 6 a. However, in order to avoid, as far as possible, interferences between two model cars 10 and thus disturbances in the energy transmission, the bus bars 14 c, 14 d of the second lane 6 b are flowed through by an electrical current with a frequency which is at least one and a half times as high as the first frequency. In the present exemplary embodiment, the second frequency is 600 kHz.

Reference is now made, in addition, to FIGS. 6 and 7, which show by way of example wiring variants of the two bus bars 14 a, 14 b, 14 c, 14 d with reference to the first lane 6 a of the two lanes 6 a, 6 b of the track 4.

FIG. 6 shows a first wiring variant in which the two bus bars 14 a, 14 b of the first lane 6 a are wired electrically in parallel. This allows use to be made of the doubled conductor cross section of the two bus bars 14 a, 14 b, so that a doubling of the current strength applied to the bus bars 14 a, 14 b becomes possible.

FIG. 7 shows a second wiring variant in which the two bus bars 14 a, 14 b of the first lane 6 a are wired electrically in series. Thus, the two bus bars 14 a, 14 b form a double conductor loop, so that the efficiency of the energy transmission is improved.

Reference is now made to FIG. 8.

This shows a second exemplary embodiment of a track 4′ which, in contrast to the track 4 illustrated in FIG. 1, only has two recesses 8 a, 8 b, in each of which a further exemplary embodiment of a bus bar 14 a′, 14 b′ is fitted.

The structure of the bus bars 14 a′, 14 b′ according to this exemplary embodiment will be explained with reference to the bus bar 14 b′ assigned to the second lane 6 b.

The bus bar 14 b′ has a u-formed profile with a groove base 32 and two flanges 34 extending from the groove base 32 which in the present exemplary embodiment extend parallel. Extending from each of the flanges 34 is a tongue 36 which extends within the plane of the surface of the track 4′.

The bus bars 14 a′, 14 b′ according to this exemplary embodiment are in each case formed in a single piece and of the same material. Furthermore, according to this exemplary embodiment the bus bars 14 a′, 14 b′ are manufactured of a magnetic material. In this way, here too the model car 10 can be held in the lane 6 a through magnetic force by means of a permanent magnet (not shown) which interacts with the bus bar 14 a′. In particular, the two tongues 36 provide an enlarged surface on which the magnetic force can act, so that a magnet of reduced size can be used in the model car 10 which takes up less construction space.

Furthermore, the two bus bars 14 a′ 14 b′ are fitted into the respective recesses/grooves 8 a, 8 b such that the u-formed bus bars 14 a′, 14 b′ are open in an upwards direction, so that the guide element 30, for example a pin of the model car 10, can engage in the u-formed bus bar 14 a′ in order in this way to guide the model car 10 along the lane 6 a defined by the recess 8 a. Thus, this track 4′ has a particularly simple structure with only one bus bar 14 a′, 14 b′, in the present exemplary embodiment arranged centrally, for each of the lanes 6 a, 6 b, wherein the bus bars 14 a′, 14 b′ in each case have a double function, namely to serve as bus bar and as guide groove for the model car.

While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.

Thus, having described the invention, what is claimed is: 

1. A model car including a coil arrangement, said coil arrangement having at least one substrate and at least one first coil portion and a second coil portion, wherein the substrate, which is manufactured from an electrically insulating material, has a basic shape extending in a planar manner with an upper side and an underside opposite the upper side, wherein at least the first coil portion and the second coil portion form a coil winding, wherein the first coil portion is arranged on the upper side and the second coil portion is arranged on the underside of the substrate.
 2. The model car of claim 1, wherein the substrate has a ferrite core.
 3. The model car of claim 1, wherein the substrate has a first circuit board portion and a second circuit board portion, wherein an upper side of the first circuit board portion forms the upper side of the substrate and an underside of the second circuit board portion forms the underside of the substrate.
 4. The model car of claim 3, including connecting lines extending through the first circuit board portion and the second circuit board portion in order to connect the first coil portion with the second coil portion electrically.
 5. The model car of claim wherein an underside of the first circuit board portion is arranged on an upper side of the ferrite core and an upper side of the second circuit board portion is arranged on an underside of the ferrite core.
 6. The model car of claim 1 wherein coil portions form at least three to eight, in particular five coil windings.
 7. The model car of claim 1, wherein a screw vector of the coil arrangement lies substantially within the plane of the substrate.
 8. The model car of claim 1, wherein the substrate has a first direction of extension which extends between the two coil portions, a second direction of extension (I) which extends at right angles to the first direction of extension (I) and a third direction of extension (III) which extends at right angles to the first direction of extension (I) and to the second direction of extension (II), wherein a screw vector (S) of the coil arrangement extends substantially in the direction of the second direction of extension (II) and/or the third direction of extension (III).
 9. (canceled)
 10. The model car of claim 2, wherein the substrate has a first circuit board portion and a second circuit board portion, wherein an upper side of the first circuit board portion forms the upper side of the substrate and an underside of the second circuit board portion forms the underside of the substrate.
 11. The model car of claim 4 wherein coil portions form at least three to eight, in particular five coil windings.
 12. The model car of claim 11, wherein the substrate has a first direction of extension (I) which extends between the two coil portions, a second direction of extension (II) which extends at right angles to the first direction of extension (I) and a third direction of extension (III) which extends at right angles to the first direction of extension (I) and to the second direction of extension (II), wherein a screw vector (S) of the coil arrangement extends substantially in the direction of the second direction of extension (II) and/or the third direction of extension (III). 